Filter valves for energy efficient and inexpensive cleaning of dust filters

There are a number of technologies to clean dust filters effectively and inexpensively are available. One of the most efficient is the air-blasting technique. The basic principle is straightforward - a short, intense pulse of air blasts into the soiled filter element. Dust and loose dirt from the filter fall to the ground and can be removed from there. Following the short cleaning cycle the filter is ready and the filter system can again operate at full capacity.

how to clean dust filters

Filter valves for air-blasting have been developed to allow efficient and inexpensive cleaning. Top priorities in the developers’ specification are to optimise the filter cleaning, reduce air consumption and prolong the valves' service life. To achieve optimum cleaning with the compressed air pulse, the pressure in the filter has to reach the set point very quickly. This means that the valves must open fully within a few milliseconds. In fact extremely fast opening and closing times are essential for effective, intensive cleaning. This determines the economical operation of a valve. The air pulse must return to zero as quickly as possible, as any minor delay will only consume air and cost money.

Heavy-duty filter valve for pressure of up to 12 bar

For the development of its latest filter valves, Buschjost wanted to come up with a product that allows for greater cleaning effectiveness, using air blasts of higher pressure. Apart from its reliable 2/2-way valves designed for a maximum operating pressure of 8 bar, Buschjost now offers these valve types for operating pressures of up to 12 bar.

These new products have a number of commercial advantages for plant operators: on the one hand, filters are cleaned more effectively, on the other, longer and larger filter hoses can be used in the filter systems.

At the heart of the new sturdy filter valve is a high-performance membrane made from a special TPE compound that has been tried and tested in many different applications. The TPE membrane is resistant even to the most aggressive chemicals.

High pressure air pulse

The design of the housing geometry, the control holes and especially the diaphragm seal is impressive. Kv value is a de¬termining factor of the flow rate and is considerably higher in this valve series. The Kv value of the G 1½ valve, for example, is approximately 30 % higher than that of comparable stand¬ard models. Pressure-rise time is crucial in ensuring effec¬tive cleaning; the pulse of the valve reaches its maximum after a few milliseconds, letting the valve open around 25 % faster than conventional dust filter valves. Reduced pressure rise times and an improved flow rate result in considerably stronger air pulses. This often allows the required operating pressure to be reduced, leading to significant savings in operating costs.

In addition to the flow rate and the pres¬sure rise time, the pressure loss in the valve determines the quality and efficiency of a filter valve. The lower the pressure difference between the valve outlet and the pressure of the internal tank when the valve is 100 % open, the lower the operating pressure can be. This has a positive effect on the energy balance of the equipment. Here, customers again feel the direct benefits of the use of modern simulation technologies. The pressure drop across the valve can be decreased by approximately 15 %.